1. Field of the Invention
The present invention relates to an electrical junction box mounted on a vehicle or the like as a moving object.
2. Description of the Related Art
Various electronic devices such as a head lamp, a tail lamp, a starter motor, and an air conditioner motor are mounted on a vehicle as a moving object.
A junction block is arranged at a proper position in a vehicle for supplying electric power to the various electronic devices. Various electric circuit units composed of fuses, relays or the like are gathered in the junction block.
Incidentally, because the junction box includes fuses, relays, or bus bars, the junction box is also referred as a fuse block, a relay box, or collectively referred to as an electrical junction box. In this embodiment, the fuse block, the relay box, and the junction block are collectively referred to as the electrical junction box.
A conventional junction box includes: a box main body; and an electric-power-distributing unit received in the box main body. The box main body is formed in a flattened box shape. The box main body includes: a lower cover; and an upper cover attached to each other for receiving the electric-power-distributing unit. The lower and upper covers are made of insulating synthetic resin, and molded by injection molding.
The electric-power-distributing unit includes: a printed wiring board; a plurality of connectors mounted on the printed wiring board; a fuse-holding portion holding a plurality of fuses mounted on the printed wiring board; and relays as a plurality of electric components mounted on the printed wiring board. A conductive pattern of the printed circuit board electrically connects terminals of the connectors with the fuses and the relays according to a predetermined pattern.
The connector is exposed outside of the box main body via a through-hole penetrating an outer wall of the box main body. At least one of the connectors is fitted with a connector attached to an end of a power source cable connected to a power source such as a battery or a power generator mounted on the vehicle. Other connectors are fitted with connectors attached to ends of a wiring harness connected to various electronic devices mounted on the vehicle.
The fuse-holding portion is exposed outside of the box main body via a through-hole penetrating an outer wall of the box main body. The fuse-holding portion holds a plurality of fuses. The relay is mounted on the printed wiring board, and received in the box main body.
In the above conventional electrical junction box, electric power supplied from the connector connected to the power source is distributed by a conductive pattern of the printed wiring board, and passed through the fuses and relays, and then supplied to various electronic devices via electric wires in the wiring harness.